The invention pertains to methods of electrolytically forming materials comprising at least two elements, and in particular applications pertains to methods of forming materials comprising tantalum and titanium. The invention also pertains to mixed metal materials, such as materials comprising tantalum and titanium. In addition, the invention pertains to sputtering targets made of mixed metal materials, such as targets comprising tantalum and titanium.
Numerous applications exist in which it can be desired to form materials comprising two or more elements provided in a substantially homogenous distribution of the elements. For instance, it can be desired to form physical vapor deposition (PVD) targets comprising two or more metallic elements uniformly distributed throughout the targets. Frequently, it is difficult to combine two or more elements into a homogenous mixture when their melting points and/or densities are far apart. For example, there could be an interest to develop an alloyed titanium-tantalum target. However, making an alloyed titanium-tantalum ingot is impractical with conventional techniques. A large difference between the melting points of titanium and tantalum (1670xc2x0 C. for titanium and 2996xc2x0 C. for tantalum) makes it impractical to melt titanium together with tantalum in an e-beam furnace. Titanium would be simply vaporized at the melting point of tantalum. In addition, the large difference in densities (4.5 g/cm3 for titanium and 16 g/cm3 for tantalum) would be troublesome when powder processing an alloy comprising both titanium and tantalum. Segregation could too easily take place. Additionally, because of a generally higher gas content, powder processed targets are less preferred than melted and wrought targets.
It would be desirable to develop new methods for forming mixed metal alloy ingots, and it would be particularly desirable to develop methods which could be utilized to form titanium and tantalum alloy ingots. More generally, it would be desirable to develop new methods for forming products comprising mixtures of two or more elements. It is known that if an alloyed feedstock is melted, the melting point of the feedstock is between the melting points of components. Specifically, if an alloyed titanium and tantalum piece were melted, it would melt at a temperature in between the melting points of titanium and tantalum. The higher the portion of titanium in the piece, the lower would be the melting temperature. The lowering of the melting temperature could make the melting process much easier than for a material comprising pure tantalum. Therefore, it could be desirable to develop new methods for preparing tantalum materials diluted with titanium to form alloyed tantalum feedstocks for melting processes.
In one aspect, the invention encompasses a method of forming a material which comprises at least two elements. More specifically, the method comprises providing an electrolytic cell comprising a cathode, an anode, and an electrolytic solution extending between the cathode and anode. A metallic product is electrolytically formed within the electrolytic cell. The forming of the metallic product comprises primarily electrorefining of a first element of the at least two elements and primarily electrowinning of a second element of the at least two elements.
In another aspect, the invention encompasses a method for electrolytically forming a material, wherein an electrolytic cell is provided which comprises a cathode, at least two anodes, and an electrolytic solution extending between the cathode and the at least two anodes. The at least two anodes comprise first and second anodes having different concentrations of a first element relative to another. The electrolytic solution comprises a compound which includes a second element. A metallic product is electrolytically formed with the electrolytic cell. The metallic product comprises a mixture of the first and second elements.
In yet another aspect, the invention encompasses a method for electrolytically forming a product which comprises a mixture of tantalum and titanium.
In yet another aspect, the invention encompasses a mixed metal product comprising at least two elements, such as a product comprising tantalum and titanium. The product comprising a mixture of the at least two elements can be considered an alloyed product, and can be used as feedstock for melting processes. In particular, a product comprising titanium and tantalum can be melted in an e-beam furnace to form a titanium-tantalum alloy ingot for further processing into a sputtering target.